Apparatus and method for data processing for IC tags and image forming device with the apparatus

ABSTRACT

The invention relates to an apparatus and method for data processing for IC tags and an image forming device capable of recording an image onto a conveying medium on which IC tags are mounted. The apparatus and method set up a state that enables reliable radio communication between a reader/writer and an IC tag and read and/or write electronic information from/to IC tags. The reader/writer&#39;s antenna to face IC tags mounted on the conveying medium, arranged in multiple rows and columns in the conveyance direction, is skewed so that the IC tags pass sequentially under the antenna and each IC tag can be identified. The reader/writer reads and/or writes electronic information associated with the thus identified IC tag.

This application is based on application No. 2005-126360 filed in Japan,the contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an apparatus and method for data processingfor IC tags and an image forming device such as a label printer. Inparticular, the invention relates to an apparatus and method for dataprocessing for IC tags by which electronic information is read fromand/or written to IC tags moving in a given direction, the IC tags beingtransported by a conveying medium on which they are mounted, and animage forming device with the data processing apparatus for IC tags.

2. Prior Art

A wireless communication device comprising a storage device, atransceiver, and an antenna is a semiconductor device from/to whichcontactless reading and/or writing of electronic information can beperformed, which is generally called a Radio Frequency Identification(RFID) device. RFID devices are used, embedded in various kinds of ICcards such as credit cards. Recently, it has been proposed to use theRFID devices for management of commercial goods by embedding them intolabels tagged to commercial goods, recording information about the goodselectronically onto them, and reading the information from them asrequired.

To read and/or write electronic information from/to such an RFID device(hereinafter referred to as an IC tag), a system is known in which aconveying medium such as recording paper on which IC tags mounted bybonding and other means is allowed to pass through a reader/writer whichperforms reading and/or writing of electronic information, electronicinformation is transmitted and received between the antenna of thereader/writer and the antenna of each IC tag, and reading and/or writingof electronic information from/to the IC tags will be performed in acontactless state.

Some reader/writer of this kind quickly reads and/or writes electronicinformation from/to IC tags mounted on a conveying medium, arranged inmultiple rows along the direction in which the conveying medium moves.In this case, the plurality of IC tags on the conveying medium aresequentially identified and electronic information for each identifiedIC tag is read from and/or written to each IC tag. To do this, theantenna of the reader/writer is moved in a direction orthogonal to thedirection of moving of the IC tags to sequentially identify the IC tagsarranged in multiple rows; this mechanism is disclosed in Japanese LaidOpen Patent Publication No. 2003-300356.

A conveying medium on which IC tags are mounted, arranged in multiplerows and columns along the direction in which the conveying medium movesis also known, which is disclosed in Japanese Laid Open PatentPublication No. 2003-331220.

Moreover, in sorting a device that uses IC tags for sorting packages, anantenna device allowing for reliable reading of electronic informationfrom IC tags is disclosed in Japanese Laid Open Patent Publication No.2004-244140. This antenna device consists of two coil antennas placed tosurround a conveyer belt for conveying packages and the two antennasextend in the direction of conveyance and are placed asymmetrically towiden the area where communication with IC tags is possible in theconveyance direction and ensure longer communication time during whichmore read operations are performed.

Furthermore, when the conveying medium on which IC tags are mounted ismoved at a constant speed, if the amount of data for electronicinformation to be read from and/or written to an IC tag is great,reading and/or writing of the information may be uncompleted during thepassage of the IC tag through the antenna coverage of the reader/writer.When a plurality of IC tags exist in the antenna coverage of thereader/writer, an IC tag for which reading and/or writing of electronicinformation should be performed cannot be identified and a communicationerror may take place. The use of a smaller antenna for countermeasuresagainst such error may result in incompletion of reading and/or writingof electronic data during the passage through the antenna coverage. Toaddress such a problem, a system in which multiple readers/writers ortheir antennas are provided and one of them is selected according tocondition is disclosed in Japanese Laid Open Patent Publication No.2004-082432.

The above prior art readers/writers that read and/or write electronicinformation from/to IC tags each bring about disadvantages below: needfor the mechanism to move the antenna orthogonally to the direction inwhich IC tags are conveyed (Japanese Laid Open Patent Publication No.2003-300356); provision of multiple antennas for countermeasures againstcommunication errors which may occur when a plurality of IC tags existin the antenna coverage of the reader/writer; and need for communicationerror preventing measures such as providing more spacing between IC tagson the conveying medium in the conveyance direction.

SUMMARY OF THE INVENTION

It is a primary object of this invention to provide an apparatus andmethod for data processing for IC tags, wherein the apparatus and methodset up a state that enables reliable radio communication with aplurality of IC tags mounted on a conveying medium and read and/or writeelectronic information from/to the IC tags, and to provide an imageforming device capable of recording an image onto the conveying mediumon which the IC tags are mounted.

It is another object of this invention to provide the data processingapparatus for IC tags that sequentially reads and/or writes electronicinformation by radio communication from/to each of a plurality of ICtags mounted on a conveying medium, arranged in multiple rows andcolumns along the conveyance direction, each tag having a storage deviceand a wireless transceiver.

It is yet another object of this invention to provide the dataprocessing method for IC tags that sequentially reads and/or writeselectronic information by radio communication from/to each of aplurality of IC tags mounted on a conveying medium, arranged in multiplerows and columns along the conveyance direction, each tag having astorage device and a wireless transceiver.

It is a further object of this invention to provide the image formingdevice that reads and/or writes electronic information from/to aplurality of IC tags mounted on a conveying medium and can record animage related to the IC tags on the conveying medium on which the ICtags are mounted.

Other objects of this invention will be apparent from the followingdetailed description with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a conveying medium to which IC tags areattached.

FIG. 2 is a front view of a data processing apparatus that performswriting/reading of electronic information to/from the IC tags to explainits configuration.

FIG. 3 is a front view of an IC tag to explain its configuration.

FIG. 4 is a front view of an antenna of a reader/writer to explain itsconfiguration.

FIG. 5 is a block diagram of a controller that exerts control of thedata processing apparatus.

FIG. 6 is a diagram to explain identifying IC tags and sequence in whichwriting/reading of electronic information to/from the tags will beperformed, according to a first embodiment of the invention.

FIG. 7 is a diagram to explain how to calculate a skew angle of thereader/writer's antenna, according to the first embodiment.

FIG. 8 is a cross-sectional view of a label printer that records visibleinformation on a conveying medium on which IC tags are mounted andrecords electronic information to the IC tags to explain itsconfiguration.

FIG. 9 is a diagram to explain how IC tags are arranged on the conveyingmedium, according to a second embodiment of the invention.

FIG. 10 is a diagram to explain identifying IC tags and sequence inwhich writing/reading of electronic information to/from the tags will beperformed, according to a third embodiment of the invention.

FIGS. 11( a) and 11(b) are diagrams to explain identifying IC tags andrecording electronic information to the tags by horizontally turningback and forth of the antenna, according to the third embodiment.

FIGS. 12( a), 12(b), and 12(c) are diagrams to explain identifying ICtags and recording electronic information to the tags by horizontallyturning back and forth of the antenna, according to the third embodiment(continued).

FIGS. 13( a), 13(b), and 13(c) are diagrams to explain identifying ICtags and recording electronic information to the tags by horizontallyturning back and forth of the antenna, according to the third embodiment(continued).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following will describe typical embodiments of this invention.

First Embodiment

FIG. 1 is a front view of a conveying medium on which IC tags aremounted. Wireless communication devices (hereinafter referred to as ICtags) 11, which will be described later, are mounted on the medium,arranged at fixed pitch p1 in multiple rows (three rows in FIG. 1) inparallel with the direction of arrow a in which the conveying medium 12moves (the direction of conveyance of the IC tags) and in multiplecolumns along the direction of arrow a. The conveying medium 12 is, forexample, continuous-form paper or other similar media for use in a labelprinter or the like, on which visible information such as desired textis printed. After electronic information is read from and/or written tothe IC tags 11 by a data processing apparatus which will be describedlater, the medium is cut into labels with predetermined dimensions andeach label having an IC tag will be stuck to a commercial product or thelike. Although, by way of example, labels are produced in thisembodiment, it goes without saying that the scope of application of theinvention involves similar objects such as cards, tags, and hangtags.

The conveying medium 12 is not limited to the above one in thisembodiment and any similar medium on which IC tags 11 can be mounted maybe used. For example, cut sheets instead of the continuous-form papermay be used.

In FIG. 1, the contour of an IC tag 11 corresponds to an area(hereinafter referred to as an effective area of an IC tag) where thefield intensity of the IC tag's antenna is a predetermined signal levelor more enabling normal communication with a reader/writer 14 and itsantenna 15 which will be described later. In the following description,the term “IC tag” refers to an IC tag and its antenna and the contour ofan IC tag refers to the effective area of the IC tag.

FIG. 2 is a front view of the data processing apparatus 10 that performswriting/reading of electronic information to/from the IC tags 11 toexplain its configuration. The conveyance mechanism is constructed suchthat the conveying medium 12 moves at a constant speed in the directionof arrow a with a conveyor 21 consisting of pairs of transport rollers18, 19 driven by a motor 17 for conveyance.

When the conveying medium 12 moves at a constant speed in the directionof arrow a, the IC tags mounted on it at fixed intervals also move at aconstant speed in the direction of arrow a and the forward edge of an ICtag 11 is detected by a tag position sensor 24 located above and closeto the transport path of the conveying medium.

The data processing apparatus 10 is located apart from the conveyingmedium 12, facing the side of the conveying medium 12 having the IC tagsmounted thereon. Inside the data processing apparatus 10, areader/writer 14 that reads/writes electronic information from/to ICtags is placed and its antenna 15 is installed to extend from an antennaadjuster 20 which will be described later. The antenna adjuster 20 isdriven by a pulse motor 23.

FIG. 3 is a front view of an IC tag 11 to explain its configuration. TheIC tag 11 is a semiconductor device from/to which reading/writing ofelectronic information can be performed in a contactless manner. The tagconsists of a wireless transceiver 11 a including a storage device forstoring electronic information and an antenna 11 b laid on itsperiphery. By radio communication with the reader/writer 14, electronicinformation can be written and read to/from the tag. In thisapplication, the IC tag 11 comprising the wireless transceiver 11 a andthe antenna 11 b is called as an IC tag 11.

In the reader/writer 14, when electronic information inputted via aninput means, which is connected to a controller 30 for the dataprocessing apparatus 10, as will be described later, such as a computer(PC) 28 connected to the data processing apparatus 10, or electronicinformation to be recorded, entered via an operation panel 29 or thelike are inputted, the inputted electronic information is written to theIC tag 11 by radio communication through its antenna 15 mounted to thereader/writer 14, and output to the computer (PC) 28 the electronicinformation of the IC tag 11 read from the reader/writer 14 through itsantenna 15.

FIG. 4 is a front view of the antenna 15 of the reader/writer 14 toexplain its configuration. The antenna 15 is formed by a wire 15 a laidin loops on a resin board 15 b with a high dielectric constant andconnected to the reader/writer 14. The coverage of the antenna 15 is arange in which the field intensity of electromagnetic waves radiatedfrom the antenna is a predetermined intensity or more and here itcorresponds to a region delimited by outside lines formed by the wire 15a laid in roughly loops.

The antenna 15 is placed above and close to, being not in contact with,moving IC tags 11 on the conveying medium 12 and configured so that itsangle can be adjusted by the antenna adjuster 20, which will bedescribed later, to allow for identifying each of the IC tags 11 mountedon the conveying medium 12.

The antenna adjuster 20 horizontally turns the resin board 15 b with ahigh dielectric constant on which the wire 15 a of the antenna 15 islaid out by a predetermined angle θ by the pulse motor 23 and isconfigured by a known means. Calculating the angle θ by which theantenna 15 should be turned horizontally and controlling the antennaadjuster 20 to set the antenna 15 skew at the calculated angle θ arecarried out by the controller 30 which will be described later.

FIG. 5 is a block diagram of the controller 30 that exerts control ofthe data processing apparatus 10. The core of the controller 30 is a CPU31 and, to I/O ports of the CPU 31, a ROM 25 for storing software forcontrol, a RAM 26, an EEPROM 27, the tag position sensor 24, thecomputer (PC) that outputs information to be recorded, and the operationpanel 29 are connected. In addition, the reader/writer 14, the motor 17for conveyance to drive the conveying medium 12, and the pulse motor 23to drive the antenna adjuster 20 are connected to the CPU 31.

When the forward edge of an IC tag 11 is detected by the tag positionsensor 24, based on a time when the IC tag 11 has been detected andinformation for the speed at which the conveying medium 12 moves in thedirection of arrow a (known speed V), the effective area of the antenna15 of the reader/writer 14, and the effective area of the IC tag 11, thecontroller 30 calculates timing to enable normal communication betweenthe reader/writer and the IC tag and calculates and determines timing tostart a motion of the reader/writer 14.

The controller 30 calculates the angle θ by which the antenna 15 shouldbe turned horizontally by a calculation formula which will be providedlater and drives the pulse motor 23 of the antenna adjuster 20 to turnthe antenna 14 by the angle θ. Moreover, the controller 30 calculatesthe maximum data size that can be written to an IC tag by a calculationformula which will be provided later and compares the thus calculatedmaximum data size with the amount of data for electronic information tobe written to the IC tag, which is held on the PC. If the maximum datasize is greater, the controller 30 allows the reader/writer to write theelectronic information; if the maximum data size is smaller, thecontroller 30 alerts the reader/writer to the impossibility to write.

Electronic information write operation that is executed under thecontrol of the controller 30 will be outlined below. When apredetermined period of time elapses after the forward edge of an IC taghas been detected, and the calculated and determined timing to enablenormal communication between the reader/writer 14 and the IC tag 11 hascome, then the antenna 15 is turned horizontally by the angle θcalculated already and radio communication between the reader/writer 14and the IC tag 11 is initiated to start writing of electronicinformation to the IC tag 11.

FIG. 6 is a diagram to explain identifying the IC tags 11 arranged inmultiple rows (three rows in this example) along the direction of arrowa in which the conveying medium 12 and the IC tags 11 move and inmultiple columns (three columns in this example) along the direction ofarrow a and sequence in which writing electronic information to the tagswill be performed. The conveying medium 12 moves at a constant speed Vin the direction of arrow a by the transport roller pairs 18, 19. Asdescribed above, the antenna 15 is skewed at the angle θ to a directionorthogonal to the direction in which the IC tags 11 move (the directionof arrow a) ((90−θ) degrees relative to the direction in which the ICtags 11 move).

Arranged on the conveying medium 12, if IC tags in an uppermost columnare labeled 11A, 11B, 11C in order from the left, IC tags in a secondcolumn are labeled 11D, 11E, 11F in order from the left, IC tags in athird column are labeled 11G, 11H, 11I in order from the left, the ICtags will pass under the antenna 15 in sequence of 11A to 11I and, thus,each IC tag 11 can be identified.

Electronic information writing is executed as follows. When an IC tag11A first enters the coverage of the antenna 15, radio communicationbetween the reader/writer 14 and the IC tag 11A takes place and theidentifier ID of the IC tag 11A is input via the reader/writer 14 to thecomputer 28. The computer 28 identifies the particular IC tag 11A by itsidentifier ID and outputs electronic information associated with therecognized IC tag 11A to the reader/writer 14. The reader/writer 14writes the input electronic information to the IC tag 11A and recordingfinishes. In the same procedure, writing electronic information tosubsequent IC tags 11B to Ill is executed sequentially. Readingelectronic information from the IC tags is also executed in the samesequence.

Now, how to calculate the angle θ at which the antenna 15 is skewed willbe described. FIG. 7 is a diagram to explain how to calculate the angleθ, where the direction of arrow a in which the conveying medium 12 movesis assumed to be Y-axis direction and the direction orthogonal to thisis X-axis direction.

The antenna 15 is set skew so that one end of the lower edge of theeffective area of the antenna 15 reaches a point P1 at the upper leftcorner of a leftmost IC tag 11P on the conveying medium, while the otherend thereof reaches a point P2 at the lower right corner of a rightmostIC tag 11Q on one row above. The angle θ of this skew of the antenna 15can be expressed by the following formula (1):tan θ=Gt/{Rw×n+Gw×(n−1)}  (1)

-   -   where    -   Rw: Length of an IC tag in the X-axis direction (mm)    -   Gw: Distance of spacing between successive IC tags in the X-axis        direction (mm)    -   Gt: Distance of spacing between successive IC tags in the Y-axis        direction (mm)    -   n: the number of IC tags sequenced in the X-axis direction.

As shown in FIG. 6, when IC tags 11 are arranged in three rows in theX-axis direction, and provided the length of an IC tag 11 in the X-axisdirection Rw=70 mm, the length of an IC tag 11 in the Y-axis directionRt=50 mm, the distance of spacing between successive IC tags in theX-axis direction Gw=20 mm, Gt=20 mm, and the number of IC tags sequencedin the X-axis direction n=3, tan θ is calculated from the formula (1) asfollows:

$\begin{matrix}{{\tan\;\theta} = {{Gt}/\left\{ {{{Rw} \times n} + {{Gw} \times \left( {n - 1} \right)}} \right\}}} \\{= {20/\left\{ {{70 \times 3} + {20 \times \left( {3 - 1} \right)}} \right\}}} \\{= 0.08}\end{matrix}$

Hence, the angle θ at which the antenna 15 is skewed will be about 4.6degrees.

Next, the maximum data size that can be written to an IC tag iscalculated. The maximum data size is the data size that can be writtenduring a range in which the effective area of an IC tag's antenna andthe effective area of the reader/writer's antenna overlap; that is, toexplain with FIG. 7, the data size that can be written during a periodafter the point P1 at the upper left corner of the IC tag 11P beingconveyed has reached the lower edge of the effective area of the antenna15 and until the point P2 at the lower right corner of the IC tag 11Qhas passed the lower edge of the effective area of the antenna 15. Themaximum data size M that can be written to one IC tag 11 can beexpressed by the following formula (2):M=[{(Rt+Gt)/V}/W]/n  (2)

-   -   where    -   Rt: Length of an IC tag in the Y-axis direction (mm)    -   Gt: Distance of spacing between successive IC tags in the Y-axis        direction (mm)    -   n: the number of IC tags sequenced in the X-axis direction    -   V: Speed at which the medium moves (mm/s)    -   W: Time to write data in units to an IC tag (ms/byte).

Provided the length of an IC tag 11 in the Y-axis direction Rt=50 mm,the distance of spacing between successive IC tags in the Y-axisdirection Gt=20 mm, the number of IC tags sequenced in the X-axisdirection n=3, the speed at which the medium moves V=90 mm/s, and thetime to write data in units to an IC tag W=3.25 ms/byte, the maximumdata size that can be written to one IC tag 11 is calculated from theformula (2) as follows:

$\begin{matrix}{\left. {M = {\left\lbrack {\left\{ {{Rt} + {Gt}} \right)/V} \right\}/W}} \right\rbrack/n} \\{= {\left\lbrack {{\left\{ {\left( {50 + 20} \right)/90} \right\} \times 1000}/3.25} \right\rbrack/3}} \\{= {79.7\mspace{14mu}{bytes}}}\end{matrix}$

In the above formula (2), {(Rt+Gt)/V}×1000 represents time (ms) afterthe point P1 at the upper left corner of the IC tag lip being conveyedhas reached the lower edge of the effective area of the antenna 15 anduntil the point P2 at the lower right corner of the IC tag 11Q haspassed the lower edge of the effective area of the antenna 15. This isdivided by the time to write data in units to an IC tag W=3.25 ms/byte,the result of which is further divided by 3, the number of IC tagssequenced in the X-axis direction 3; thereby the maximum data size thatcan be written per IC tag is calculated.

The controller 30 compares the calculated maximum data size that can bewritten to an IC tag with the amount of electronic data to be recordedto the IC tag, which is held on the PC. If the maximum data size isgreater, the controller 30 allows the reader/writer to write theelectronic information; if the maximum data size is smaller, thecontroller 30 outputs an alert signal.

FIG. 8 is a cross-sectional view of a label printer that records visibleinformation on the conveying medium on which the IC tags are mounted andrecords electronic information to the IC tags to explain an example ofits configuration. The label printer 40 is comprised of a paper feedingsection 41 in which conveying media 12 on which IC tags are mounted arestowed, a full color printer 42, the above-described data processingapparatus 10 equipped with the reader/writer 14 and the antenna 15 (seeFIG. 2), a paper ejection section 46 in which processed conveying media12 are collected, the operation panel 29, and the controller 30 (seeFIG. 5). The full color printer which is an image forming unit is toprint and record visible information associated with electronicinformation that is recorded to IC tags on a conveying medium 12 andother image information. Although a known, tandem-type full colorprinter is shown here, it goes without saying that any other type ofprinter may be employed.

As conveying media 12, continuous-form paper with pin-feed holes on bothsides in the conveyance direction is used. Tracks 43 with pins to engagethe pin-feed holes of the conveying media 12 are located along thetransport path of conveying media. The tracks 43 are driven by a drivingdevice, not shown, synchronously in conjunction with the transportroller pairs 18, 19 driven by the motor 17 for conveyance and transporta conveying medium 12 upward in FIG. 8. Downstream of the tracks 43, thefull color printer 42 is placed and a full color toner image formed onits transfer belt by a known imaging unit is transferred to a conveyingmedium 12 at a second transfer unit 42 a. The full color toner imagetransferred to the conveying medium 12 is preheated by a preheating unit44 and fixed to the medium by a flash fusing unit 45.

Conventional roller-type fixing devices apply high pressure and hightemperature to IC tags, resulting in damage to IC tags. The fixingdevice adopted in this embodiment fixes a toner image to an IC tag 11 ina contactless manner; that is, the flash fusing unit 45 emits flashinglight toward the toner image on the conveying medium preheated by thepreheating unit 44 and this heats the toner, specifically, heatsinfrared absorbents included in the toner.

The conveying medium 12 on which visible information was printed andrecorded is transported to the data processing apparatus 10 whereelectronic information is written to the IC tags and the medium isdropped into the paper ejection section 46. Thereafter, by a posthandling device, not shown, the conveying medium is cut into labels asfinished goods, each label having visible information recorded thereonwith an IC tag having electronic information recorded thereon.

Second Embodiment

A data processing apparatus of a second embodiment of the invention hasthe same reader/writer and antenna as in the first embodiment, but theantenna is not skewed. Instead, by modifying the arrangement of the ICtags on the conveying medium, each IC tag can be identified. Componentscorresponding to those described in the first embodiment are assignedthe same reference numbers and their explanation is not repeated. Thefollowing description of the second embodiment focuses on differencefrom the first embodiment.

In the data processing apparatus 10 of the first embodiment, a pluralityof IC tags 11 are arranged in multiple rows and columns along thedirection of arrow a in which the conveying medium and the IC tags move,as shown in FIG. 6, and the apparatus is configured so that each IC tag11 will be identified by skewing the antenna 15 of the reader/wrier 14at the angle θ.

FIG. 9 is a diagram to explain how IC tags 11 are arranged on theconveying medium 12, according to the second embodiment. In the secondembodiment, a plurality of IC tags 11 are arranged at fixed pitch p1 inmultiple rows (three rows in FIG. 9) in parallel with the direction ofarrow a in which the IC tags 11 move. In the direction orthogonal tothis (a direction perpendicular to the arrow a), the IC tags arearranged in multiple columns. In each column, second-row andsubsequent-row tags are shifted back by a fixed distance d to the one onthe preceding row in the direction of arrow a. In other words, a linepassing through the centers of the IC tags 11 arranged in each column isskewed at an angle β to the direction orthogonal to the direction inwhich the IC tags 11 move.

When the IC tags 11 are arranged as above, as the conveying medium andthe IC tags 11 move, the IC tags in each column sequentially reach theeffective area of the antenna 15 of the reader/writer placedorthogonally to the direction in which the IC tags move. Thus, each ICtag can be identified without skewing the antenna 15 of thereader/writer. Each IC tag can be identified properly by setting theskew angle β of the line passing through the centers of the IC tagsarranged in each column to an angle calculated by the same calculationformula as used to obtain the angle θ at which the antenna of thereader/writer is skewed in the above-described configuration.

According to the second embodiment, the antenna adjuster 20 (see FIG. 2)to skew the reader/writer antenna 15 at the angle θ is eliminated fromand the structure of the data processing apparatus 10 can be madesimpler.

Third Embodiment

This section describes a data processing apparatus of a third embodimentof the invention. The above-described data processing apparatus of thefirst embodiment fixes the skew angle of the reader/writer antenna to apredetermined angle θ determined by calculation and reads and/or writeselectronic information from/to IC tags being conveyed. On the otherhand, in the third embodiment, the apparatus reads and/or writeselectronic information from/to IC tags, while changing the skew angle ofthe reader/writer antenna in conjunction with the conveyance of the ICtags. The data processing apparatus of the third embodiment is capableof identifying each IC tag positively and reliable reading and/orwriting of electronic information, even if a plurality of IC tags arearranged closely with each other on the conveying medium.

FIG. 10 is a diagram to explain identifying IC tags and sequence inwhich reading/writing of electronic information from/to the tags will beperformed, according to the third embodiment. Components correspondingto those described in the first embodiment are assigned the samereference numbers and their explanation is not repeated. The followingdescription of the third embodiment focuses on difference from the firstembodiment.

In the data processing apparatus 10 of the third embodiment, IC tags 11are arranged at fixed pitch p1 in multiple rows (three rows in FIG. 10)along the direction of arrow a in which the conveying medium 12 and theIC tags 11 move and in multiple columns. The conveying medium 12 movesat a constant speed V in the direction of arrow a by the transportroller pairs 18, 19.

The antenna 15 is placed above and close to, being not in contact with,moving IC tags 11 on the conveying medium 12. To identify a plurality ofIC tags 11 mounted on the conveying medium 12, the antenna is driven bythe antenna adjuster 20 to turn back and forth horizontally around thecenter S of the length of the antenna 15 (see FIGS. 11 to 13) by apredetermined angle θ in the direction in which the conveying medium 12(with the IC tags 11) moves and in the reverse direction. Although theantenna 15 appears to move downward, as depicted in FIG. 10, thisdepicts its relative position to the moving conveying medium 12 and itturns back and forth around the center S by predetermined angle θhorizontally, not downwardly. The pivot point of turning of the antenna15 is not necessarily the center S; for example, the pivot point may benear to one end of the antenna 15.

The antenna adjuster 20 horizontally turns back and forth the resinboard 15 b with a high dielectric constant on which the wire 15 a of theantenna 15 is laid out by predetermined angle θ by the pulse motor 23and is configured by a known means.

The maximum angle θmax (degrees) of turning of the antenna is expressedby the following formula (3):tan θmax=P1/Q  (3)

-   -   where    -   P1: Pitch by which IC tags are separated, sequenced on the        conveying medium in the conveyance direction (mm)    -   Q: Entire width of a sequence of IC tags (including intervals        between IC tags) on the conveyance medium in the direction        orthogonal to the conveyance direction (mm)

Speed α(degrees/sec) at which the antenna 15 turns is expressed by thefollowing formula (4):α=θmax/(P1/V)  (4)

-   -   where    -   P1: Interval by which IC tags are separated, sequenced on the        conveying medium in the conveyance direction (mm)    -   V: Speed at which the medium moves (mm/s)

In FIG. 10, if upper IC tags on the conveying medium are labeled 11A,11B, 11C in order from the left, IC tags in one column below are labeled11D, 11E, 11F, IC tags in one column below are labeled 11G, 11H, 11I,the IC tags will pass under the antenna 15 in sequence mentioned and,thus, each IC tag 11 can be identified.

Recoding electronic information that is executed under the control ofthe controller 30 will be outlined below. When an IC tag 11A firstenters the coverage of the antenna 15, radio communication between thereader/writer 14 and the IC tag 11A takes place and the identifier ID ofthe IC tag 11A is input via the reader/writer 14 to the computer 28. Thecomputer 28 identifies the particular IC tag 11A by its identifier IDand outputs electronic information associated with the recognized IC tag11A to the reader/writer 14, and the reader/writer 14 writes theelectronic information to the IC tag 11A. In the same procedure, writingelectronic information to subsequent IC tags 11B to 11I is executedsequentially. Reading electronic information is also executed in thesame way.

With reference to FIGS. 11( a) and 11(b), FIGS. 12( a) to 12(c), andFIGS. 13( a) to 13(c), the following will describe identifying IC tagsand recording electronic information to the tags by horizontally turningback and forth of the antenna 15. In the following description, thedirection of arrow a in which the conveying medium 12 moves is assumedto be Y-axis direction and the direction orthogonal to this is X-axisdirection. When identifying IC tags 11 and recording electronicinformation to tags are performed by horizontally turning back and forthof the antenna 15, the conveying medium is assumed to continue to moveat the predetermined speed V.

Based on the above calculation formulas (3) and (4) the maximum angleθmax by which the antenna 15 is skewed and the speed α at which theantenna 15 is turned is calculated and set on the controller 30. Theconveying medium 12 is transported and the tag position sensor 24detects the first IC tag.

Then, upon the elapse of a predetermined period of time, the antenna 15that is at ½ P1 ahead of the forward edge of the IC tag, set parallelwith the X axis, is assumed to be in its initial state and a motion ofhorizontally turning back and forth to skew the antenna 15 starts. FIGS.11( a) and 11(b) show a positional relation between the antenna 15 inthe initial state and IC tags 11.

When the antenna becomes the initial state, the antenna 15 motion ofhorizontally turning back and forth starts. For explanatory convenience,the following will describe an operation of recording electronicinformation to IC tags in the second column, which begins from the statethat the antenna 15 has returned to its initial position, as shown inFIG. 11( b), after recording electronic information to IC tags 11 in thefirst column is finished.

After recording electronic information to the IC tags 11 in the firstcolumn is finished, when the antenna 15 returns to its initial position,the antenna 15 lies at intermediate position between the first column ofIC tags 11 and the second column of IC tags 11, separated by ½ P1 fromboth the first and second columns of IC tags.

The antenna 15 begins to turn counterclockwise around the center S (seeFIG. 12( a)). The antenna 15 continues to turn counterclockwise (seeFIG. 12( b)) up to the maximum angle θmax (see FIG. 12( c)). At thistime, the center line of the antenna 15 lies over the sequence of the ICtags.

Turned to the maximum angle θmax, the antenna 15 begins to turnclockwise, reversely, around the center S (see FIG. 13( a)). The antenna15 continues to turn clockwise (see FIG. 13( b)) and returns to itsinitial position. The antenna 15 lies at intermediate position betweenthe second column of IC tags and the third column of IC tags, separatedby ½ P1 from both the second and third columns of IC tags (see FIG. 13(c)).

While the antenna turns counterclockwise from its initial position andturns clockwise back to the initial position as above, the reader/writer14 writes electronic information by radio communication to the IC tagsthrough the antenna 15.

By repeating the same motion of the antenna, the reader/writer writeselectronic information to the IC tags on the medium sequentially. Whenwriting electronic information to all the IC tags is finished, the writeoperation terminates.

As fully described above, according to one aspect of this invention, thedata processing apparatus for IC tags which reads and/or writeselectronic information from/to IC tags, each tag having a storage deviceand a wireless transceiver, sets its antenna skew at a predeterminedangle to the direction in which the IC tags move and sequentially readsand/or writes electronic information to each IC tag.

This apparatus facilitates identifying each IC tag, even if a greatnumber of IC tags are mounted on the conveying medium. This inventioncan provide a highly reliable data processing apparatus for IC tagscapable of reading and/or writing of electronic information from/to agreat number of IC tags.

According to another aspect of this invention, the data processingapparatus for IC tags which reads and/or writes electronic informationfrom/to IC tags, each tag having a storage device and a wirelesstransceiver, reads and/or writes electronic information from/to each ofa plurality of IC tags mounted on the conveying medium, while turningback and forth the antenna accordingly as the IC tags move.

This apparatus has a higher capability of identifying IC tags andfacilitates identifying IC tags, even if the IC tags are arrangedclosely with each other. This invention can provide a highly reliabledata processing apparatus for IC tags capable of reading and/or writingof electronic information from/to a great number of IC tags at highspeed.

Moreover, the image forming device including the data processingapparatus for IC tags of this invention can perform recording visibleinformation to conveying media and reading and/or writing electronicinformation from/to IC tags simultaneously and can produce media with ICtags at high speed and efficiency.

Although the present invention has been fully described by way ofexamples with reference to the accompanying drawings, it is to be notedthat various changes and modifications will be apparent to those skilledin the art. Therefore, unless otherwise such changes and modificationsdepart from the scope of the present invention, they should be construedas being included herein.

1. A data processing apparatus for IC tags comprising: a reader/writerwhich reads and/or writes electronic information from/to IC tags whichare mounted on a conveying medium and conveyed in a given direction, theIC tags each having a storage device and a wireless transceiver; anantenna of the reader/writer for radio communication between saidreader/writer and an IC tag, wherein said antenna is set skew at apredetermined angle to the direction in which the IC tags move and saidreader/writer reads and/or writes electronic information by radiocommunication from/to each of said IC tags mounted on the conveyingmedium sequentially; an antenna adjuster which adjusts the skew angle ofsaid antenna; and a controller which determines the angle of the antennato the direction in which the IC tags move, based on information aboutthe arrangement of the IC tags mounted on said conveying medium, andworks said antenna adjuster to set the antenna skew at said angle.
 2. Adata processing apparatus for IC tags, comprising: a reader/writer whichreads and/or writes electronic information from/to IC tags which aremounted on a conveying medium and conveyed in a given direction, the ICtags being arranged in a plurality of rows along the given direction,each row containing a plurality of IC tags, and each IC tag having astorage device and a wireless transceiver; and an antenna of thereader/writer for radio communication between said reader/writer and anIC tag; wherein when said IC tags are mounted on said conveying medium,arranged in a plurality of rows along the given direction and in aplurality of columns across the given direction, and wherein in eachcolumn, second-row and subsequent-row IC tags are shifted back from oneon a preceding row in the given direction by a fixed distance d from thetag in the preceding row, such that a line passing through the centersof the IC tags in each column is skewed at an angle β to the directionorthogonal to the given direction, such that said angle β is determinedfrom the formula:${\tan\mspace{14mu}\beta} = \frac{G_{t}}{{R_{w}*n} + {G_{w}*\left( {n - 1} \right)}}$wherein: G_(t) is a distance of spacing between successive IC tags inthe direction of travel, in mm; G_(W) is a distance of spacing betweensuccessive IC tags in a direction orthogonal to the direction of travelof the IC tags, in mm; R_(W) is a length of an IC tag in the directionorthogonal to the direction of travel of the IC tags, in mm; and n isthe number of IC tags sequenced in the direction orthogonal to thedirection of travel of the IC tags, in mm; and wherein said antenna isperpendicular to the given direction.
 3. A data processing apparatus forIC tags, comprising: a reader/writer which reads and/or writeselectronic information from/to IC tags which are mounted on a conveyingmedium and conveyed in a given direction, the IC tags each having astorage device and a wireless transceiver; an antenna of thereader/writer for radio communication between said reader/writer and anIC tag; and a controller which controls said reader/writer to readand/or write electronic information by radio communication from/to eachof a plurality of IC tags mounted on said conveying medium sequentially,and an antenna adjuster that turns back and forth the position of saidantenna around a center point by an angle θ accordingly as said IC tagsare being conveyed.
 4. An image forming device, comprising: areader/writer which reads and/or writes electronic information from/toIC tags which are mounted on a conveying medium and conveyed in a givendirection, the IC tags each having a storage device and a wirelesstransceiver; an antenna of the reader/writer for radio communicationbetween said reader/writer and an IC tag; a controller which controlssaid reader/writer to read and/or write electronic information by radiocommunication from/to each of a plurality of IC tags mounted on saidconveying medium sequentially, an antenna adjuster that turns back andforth the position of said antenna around a center point by an angle Aaccordingly as said IC tags being conveyed; and a printer which forms animage on the conveying medium on which said IC tags are mounted.
 5. Amethod for reading and/or writing electronic information from/to IC tagswhich are mounted on a conveying medium and conveyed in a givendirection, the IC tags each having a storage device and a wirelesstransceiver, said method comprising: determining a skew angle θ from theformula:${\tan\mspace{14mu}\theta} = \frac{G_{t}}{{R_{w}*n} + {G_{w}*\left( {n - 1} \right)}}$wherein: G_(t) is a distance of spacing between successive IC tags inthe direction of travel, in mm; G_(W) is a distance of spacing betweensuccessive IC tags in a direction orthogonal to the direction of travelof the IC tags, in mm; R_(W) is a length of an IC tag in the directionorthogonal to the direction of travel of the IC tags, in mm; and n isthe number of IC tags sequenced in the direction orthogonal to thedirection of travel of the IC tags, in mm; conveying in a givendirection a plurality of IC tags mounted on the conveying medium,arranged in a plurality of rows along the direction in which theconveying medium moves each row containing a plurality of IC tags; andreading and/or writing electronic information from/to each of saidplurality of IC tags sequentially in a state that an antenna of areader/writer for radio communication between said reader/writer and anIC tag is set skew at said determined skew angle θ such that if the ICtags are arranged in even alignment with each other in a column thatextends perpendicular to the given direction, each of said plurality ofIC tags will sequentially fall within the antenna coverage at differenttimes.
 6. A data processing apparatus for IC tags comprising: areader/writer which reads and/or writes electronic information from/toIC tags which are mounted on a conveying medium and conveyed in a givendirection, the IC tags being arranged in a plurality of rows along thegiven direction, each row containing a plurality of IC tags, and each ICtag having a device and a wireless transceiver; and an antenna of thereader/writer for radio communication between said reader/writer and anIC tag, wherein said antenna is set skew at an angle such that, if aplurality of IC tags is arranged in an even alignment with each other ina column that extends perpendicular to the given direction, each IC tagwill reach the antenna sequentially at different times, and saidreader/writer reads and/or writes electronic information by radiocommunication from/to each of said IC tags mounted on the conveyingmedium sequentially wherein the skew angle is determined from theformula${\tan\mspace{14mu}\theta} = \frac{G_{t}}{{R_{w}*n} + {G_{w}*\left( {n - 1} \right)}}$wherein: G_(t) is a distance of spacing between successive IC tags inthe direction of travel, in mm; G_(W) is a distance of spacing betweensuccessive IC tags in a direction orthogonal to the direction of travelof the IC tags, in mm; R_(W) is a the length of an IC tag in thedirection orthogonal to the direction of travel of the IC tags in mm;and n is the number of IC tags sequenced in the direction orthogonal tothe direction of travel of the IC tags, in mm.
 7. A data processingapparatus for IC tags comprising: a reader/writer which reads and/orwrites electronic information from/to IC tags which are mounted on aconveying medium and conveyed in a given direction, the IC tags eachhaving a storage device and a wireless transceiver; an antenna of thereader/writer for radio communication between said reader/writer and anIC tag, an antenna adjuster which adjusts a skew angle of said antenna;and a controller which determines the angle of the antenna to thedirection in which the IC tags move, based on information about thearrangement of the IC tags mounted on said conveying medium, and workssaid antenna adjuster to set the antenna skew at said angle.
 8. An imageforming device comprising: the data processing apparatus for IC tags ofclaim 1; and a printer which forms an image on the conveying medium onwhich said IC tags are mounted.